I had made a half-wave rectifier circuit in LTSpice, consisting of a sinusoidal voltage input, a diode that would be forward-biased during the positive half-cycles of the input, a 1k ohm resistor and a ground node. After wiring, I ran this circuit through a DC Sweep analysis, varying the input voltage linearly with a Start value of -400 V, a Stop value of 400 V and an Increment of 100 V (this was done to obtain the voltage transfer characteristics of the circuit, if there is a better way of obtaining these characteristics, please let me know). The plot was the voltage across the resistor vs. the varying input. The plot was as expected assuming an ideal diode model.
Then, I wanted to observe the transfer characteristics of the same circuit with the diode forward-biased during negative half-cycles. Now when I tried to obtain the same plot (using the same DC Sweep analysis), it came out strange:
The plot is strange around the -80 V - +80 V region of the horizontal axis. The trace is supposed to remain flat till 0 V and then, with a slope of -1, enter the 3rd quadrant as a straight line.
I tried again with a simple DC source, a source with no specifications, different Start/Stop/Increment values, a "signal" source, a source in series with a resistor (to check whether the source was at fault), etc. (all simulated using DC Sweep analysis). This leads me to conclude that most probably the DC Sweep analysis is not appropriate for plotting transfer characteristics or I am not defining the source properly.
Please explain why this is happening and how to obtain the expected transfer characteristics using LTSpice. Thank you.
Then, I wanted to observe the transfer characteristics of the same circuit with the diode forward-biased during negative half-cycles. Now when I tried to obtain the same plot (using the same DC Sweep analysis), it came out strange:
The plot is strange around the -80 V - +80 V region of the horizontal axis. The trace is supposed to remain flat till 0 V and then, with a slope of -1, enter the 3rd quadrant as a straight line.
I tried again with a simple DC source, a source with no specifications, different Start/Stop/Increment values, a "signal" source, a source in series with a resistor (to check whether the source was at fault), etc. (all simulated using DC Sweep analysis). This leads me to conclude that most probably the DC Sweep analysis is not appropriate for plotting transfer characteristics or I am not defining the source properly.
Please explain why this is happening and how to obtain the expected transfer characteristics using LTSpice. Thank you.